Traditionally, power converters have been utilized to provide a regulated DC output voltage from a single-phase or multi-phase AC input. Commonly, AC power is received, then rectified through a rectifier and filtered to furnish the desired DC output voltage. Further, while seeking to make power converters more efficient, today's power supply industry has also become very cost-sensitive, with low production costs being a key to success.
Increasing attention has been focused on input current total harmonic distortion (THD) due to the increasing use of nonlinear loads that tend to degrade three-phase AC line quality. Designers have fashioned many successful circuit configurations for reducing input THD and improving the power factor, commonly called power factor correction (PFC) converters. Recent designs have centered around several two-switch, three-phase PFC converter configurations that improve the input current THD thereof. In many of these power converters, the two switches are arranged in half-bridge configurations.
Another constant goal of power converter designs have been to provide a regulated DC output. Commonly, such an output voltage is generated by using a DC/DC power converter that includes an isolation transformer and a series of switches arranged in various configurations (e.g., half-bridge, full-bridge, etc.). Unfortunately, very little attention has been directed to the coordination and integration of PFC converters and DC/DC power converters. In today's electronics markets, such characteristics are quickly becoming increasingly important considerations during the design process.
Accordingly, what is needed in the art is power converter which combines PFC functions while converting phase voltages to a DC output voltage.